P1 Implicit Time Research Articles

Relationship between macular microvasculature and visual function in idiopathic macular epiretinal membrane by using OCT angiography and multifocal electroretinogram

PurposeTo investigate the relationship between microvasculature and visual function in idiopathic epiretinal membrane (iERM). MethodsThis retrospective study included 30 iERM eyes. Macular microvasculature was evaluated by optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). Visual function was evaluated by best corrected visual acuity (BCVA) and multifocal electroretinogram (mfERG). All parameters were measured in the iERM patients at baseline, 1 month, and 3 months postoperatively. Associations between macular microvasculature and visual function were evaluated. ResultsBCVA, central retinal thickness (CRT) and parafoveal vessel density (PFVD) of the deep capillary plexus (DCP) changed significantly 3 months after surgery. P1 amp density and amplitude of ring 1 decreased significantly 3 months postoperatively. P1 implicit time of ring 1 was shortened after surgery. Baseline PFVD of DCP was negatively correlated with the postoperative BCVA, and baseline BCVA was positively correlated with the postoperative BCVA. Baseline foveal avascular zone (FAZ) and P1 amplitude of ring 1 were positively correlated with the postoperative P1 amplitude of ring 1 (p < 0.05). Multiple linear regression analysis revealed that baseline PFVD of DCP was a predictor of the postoperative BCVA, and baseline FAZ was a predictor of the postoperative P1 amplitude of ring 1 (p < 0.05). ConclusionAlthough visual acuity and CRT improved after iERM surgery, visual function estimated by mfERG had a limited recovery 3 months postoperatively. Baseline PFVD of the DCP and FAZ were predictors of visual function after the iERM surgery.

Функциональное восстановление фовеа после хирургического лечения сквозных макулярных разрывов: роль отдельных изменений морфологии и перфузии сетчатки в послеоперационном периоде

Purpose. To evaluate the relationship between changes in functional and structural indicators, indicators of retinal perfusion in the fovea after surgery of full-thickness macular holes (FTMH). Material and methods. A prospective study was conducted on 62 patients (62 eyes) with FTMH stages 1–4 who underwent surgical treatment. We studied BCVA, retinal sensitivity (RS) at fixation point (FP), the fixation zone area, the amplitude and implicit time of P1 at FP, the thickness of the macular complex of ganglion cells (mcGC), the ellipsoid zone (EZ) defect area, the foveal avascular zone (FAZ) area and vessel density in the superficial and deep capillary plexuses (SCP and DCP). The correlation of indicator changes in the period from the preoperative examination to 6 months after treatment and in the period from 1 to 6 months after treatment was studied. Results. Changes in BCVA in the period from the preoperative examination to 6 months after surgery significantly correlated with changes in mcGC thickness (R=0.39, p=0.004), EZ defect area (R= –029, p=0.001) and SCP and DCP vessel density (R=0.35 and R=0.29, p=0.002); RS changes at FP correlated with the changes in EZ defect area (R= –0.31, p=0.001), and P1 amplitude with the change in the EZ defect area (R= –0.34, p=0.001) and vessel density in DCP (R= –0.29, p=0.001). In the period from 1 to 6 months after closure of the FTMH, a more significant correlation of changes in BCVA, RS and P1 amplitude of mentioned above indicators was observed. Conclusion. Processes of functional restoration of the fovea after surgery of FTMH for at least 6 months is influenced by changes in such indicators as the mcGC thickness, the EZ defect area, and vessel density of SCP and DCP. In the late postoperative period, the importance of postoperative changes in retinal perfusion increases. Key words: Full-thickness macular hole (FTMH), microperimetry, multifocal electroretinography, multimodal imaging, optical coherence tomography, optical coherence tomography-angiography

Assessment of functional changes in long‐standing type 1 diabetic patients without diabetic retinopathy with multifocal electroretinogram

Aims/Purpose: To early evaluate local functional changes in the retina of long‐standing type 1 diabetic patients (DM1) without diabetic retinopathy (DR) through the use of multifocal electroretinogram (mfERG).Methods: 46 eyes of 46 long‐standing DM1 patients without DR and 46 eyes of 46 healthy subjects were studied. Eyes with previous history of ocular diseases that could alter mfERG results were excluded. Participants were evaluated using mfERG with RETIscan recording system by Roland, following the standardized international guidelines of the International Society for Clinical Electrophysiology of Vision (ISCEV). The electrical density and implicit time of each first‐order response (K1) were measured and analysed in both study groups, as well as interocular differences.Results: Mean age was 48.00 ± 9.77 years in the DM1 group and 51.69 ± 4.75 years in the control group. The average duration of diabetes was 29.19 ± 7.85 years and the mean HbA1c level was 7.33 ± 0.9%. No statistically significant differences were found between the ages of the groups. In mfERG, a statistically significant decrease in P1 response density was recorded in the R1 ring (central 0°‐2°) in the DM1 group compared to the control subjects (p = 0.029). Additionally, the R1/R2 ratio was significantly lower in diabetic patients than in the control group (p = 0.009). There was also a statistically significant increase in the implicit time of P1 in the R5 ring (central &gt;15°) in the DM1 group compared to the control group (p = 0.027). No interocular differences were found in the DM1 group. Regarding quadrant analysis, no statistically significant differences were found in the DM1 group.Conclusions: In patients with long‐standing DM1 without RD, mfERG enables the detection of subclinical and local findings, which indicates the presence of a pre‐existing neurodegenerative process prior to the onset of retinal lesions.

Влияние исходных структурных нарушений и послеоперационного изменения перфузии на функциональное восстановление сетчатки после хирургического лечения сквозных макулярных разрывов

Purpose. To evaluate effect of preoperative local structural retinal changes and capillary perfusion in idiopathic full-thickness macular holes (FTMH) on the recovery of functional activity of the retina after surgical treatment. Materials and methods. We used optical coherence tomography (OCT) and OCT-angiography (OCT-A), microperimetry, multifocal electroretinography. In 25 eyes with FTMH the density of capillaries in the superficial and deep capillary plexus (SCP and DCP), retinal sensitivity (RS), amplitude and implicit time of P1 were studied at 13 points located at different distances from the fixation point were evaluated. Data were analyzed in the projection of the hole, intraretinal cystic changes (ICC), neuroepithelial detachment (NED) and intact retina before surgical treatment, 7 days, and 3 months after. Results. In the area of hole, ICC, and NED, in comparison with intact areas of the retina, a significant decrease in RS, an increase in implicit time and a decrease in amplitude of P1, and a decrease in capillary density in the SCP and DCP were revealed. Functional restoration of the retina with an increase in its perfusion was noted 3 months after the surgery. The correlation was found between postoperative changes in RS and changes in capillary density in the SCP in the projection of NED (R=0.32, p=0.001) and ICC (R=0.19, p=0.001), as well as in the DCP in the projection of NED and ICC (R=0.31, p=0.001). The change in the amplitude P1 in the postoperative period significantly correlated with the change in perfusion in the SCP in the projection of the NED (R=0.38, p=0.001) and the hole area (R=0.31, p=0.001), as well as in the DCP in the projection of the ICC (R=0.31, p=0.01) and in the area of NED (R=0.28, p=0.001). Conclusion. Thus, when using a multimodal topographically oriented approach, a relationship was found in the postoperative period of changes in functional parameters at various points in the macular area with changes in local perfusion at the level of both SCP and DCP, while the relationship is most significant in the projection of NED along the tear edge and in the areas of ICC. Key words: full-thickness macular hole (FTMH), microperimetry, multifocal electroretinography, multimodal imaging, optical coherence tomography, optical coherence tomography-angiography

Electrophysiological Evidence of Stroboscopic Training in Elite Handball Players: Visual Evoked Potentials Study.

Stroboscopic training enhances perceptual cognition and motor skills; however, neurophysiological mechanisms underlying this adaptation are not fully understood. This study aimed to investigate the effects of a six-week stroboscopic training program on the conductivity of the visual pathway in elite handball players, specifically related to their visual processing of retinal location and viewing conditions. The study included 22 handball players who were randomly assigned to an experimental or a control group. Both groups performed handball-specific in-situ tasks, but only the experimental group underwent stroboscopic training. Participants were assessed three times using visually evoked potential recordings measured by P100 implicit time and amplitude under three viewing conditions (dominant eye, non-dominant eye, and binocular) and two retinal locations (extra-foveal and foveal vision) before and after the six-week training period, and again four weeks later. The results showed a significant TIME vs. GROUP effect of P100 implicit time for the dominant eye in extra-foveal vision (F2,40 = 5.20, p = 0.010, ηp2 = 0.206), extra-foveal binocular viewing (F2,40 = 3.32, p = 0.046, ηp2 = 0.142), and dominant eye foveal vision (F2,40 = 4.07, p = 0.025, ηp2 = 0.169). Stroboscopic training significantly improved early visual processing by reducing the P100 implicit time for the dominant eye and binocular vision, particularly in extra-foveal vision. The improvements were more noticeable in the short compared to the long term.

The effect of retinal perfusion on the bioelectric activity of the retina in full-thickness macular holes

BACKGROUND: Information on retinal capillary perfusion in idiopathic full-thickness macular hole (FTMH) is limited, and there are no data on the possible effect of blood supply to individual areas and layers of the retina on their functional activity.&#x0D; AIM: To study the relationship between vascular perfusion in the superficial and deep capillary plexuses (SCP and DCP) and the bioelectrical activity of the retina in full-thickness macular hole.&#x0D; MATERIALS AND METHODS: Multifocal electroretinography (mfERG), optical coherence tomography (OCT), and OCT-angiography (OCTA) were performed in 18 eyes with FTMH and 10 intact eyes. In the projection of individual hexagons of the mfERG pattern, parameters of bioelectrical activity were compared with structural changes (hole, cystic changes), capillary density in the SCP and DCP.&#x0D; RESULTS: In the FTMH group, the density of capillaries in the superficial capillary plexuses correlated with P1 implicit time in the R2 ring hexagons (R = 0.23, p 0.05), in the hole zone and intraretinal cystic changes (R = 0.21 and R = 0.22, p 0.05), P1 amplitude in the hole zone (R = 0.24, p 0.05). In deep capillary plexuses, the capillary density correlated with N1 implicit time at the fixation point and the hole zone (R = 0.57 and R = 0.19, p 0.05), P1 implicit time at the hole zone (R = 0.2, p 0.05), P1 amplitude in the hexagons of the R2 and R3 rings (R = 0.46 and R = 0.44, p 0.05), more pronounced in the hole zone and cystic changes (R = 0.54 and R = 0.29, p 0.05).&#x0D; CONCLUSIONS: There is a correlation between capillary perfusion in different layers of the retina and its bioelectrical activity in FTMH. A decrease in perfusion in the deep capillary plexus of the macula with a chronic macular hole may be a predictor of a low functional prognosis in the outcome of surgical treatment of FTMH.

Retinal and Visual Pathways Involvement in Carriers of Friedreich's Ataxia.

Friedreich's ataxia (FRDA) is a rare autosomal recessive neurodegenerative disorder due to the homozygous pathological expansion of guanine-adenine-adenine (GAA) triplet repeats in the first intron of the FXN gene, which encodes for the mitochondrial protein frataxin. In the visual system, the typical manifestations are ocular motility abnormality, optic neuropathy, and retinopathy. Despite the evidence of ophthalmological impairment in FRDA patients, there is a lack of information about the morpho-functional condition of the retina and of the optic pathways in healthy heterozygous carriers of Friedreich's ataxia (C-FRDA). Ten C-FRDA subjects (providing 20 eyes) and thirty-five Controls (providing 70 eyes) underwent a complete neurological and ophthalmological examination comprehensive of functional (full-field Electroretinogram (ffERG), multifocal Electroretinogram (mfERG), Visual Evoked Potential (VEP), and Pattern Reversal Electroretinogram (PERG)) and morphological assessments (Optical Coherence Tomography, OCT) of the retina, macula, retinal ganglion cells, and visual pathways. The groups' data were compared using a two-sample t-test. Pearson's test was used to investigate the morpho-functional correlations. Statistically significant differences (p &lt; 0.01) between C-FRDA and Control eyes for the values of the following parameters were found: ffERG b-wave amplitude, mfERG Response Amplitude Densities, PERG P50 implicit time and P50-N95 amplitude, VEP P100 implicit time, Retinal Nerve Fiber Layer (RNFL) Overall, and Nasal thickness. The values of the OCT macular volume were not statistically different (p &gt; 0.01) between the two Groups. Therefore, our data suggest that, in C-FRDA, a dysfunction of retinal elements without morphological macular impairment may occur. In addition, a morphological impairment of RNFL associated with an abnormal neural conduction along the visual pathways can be also detected.

Visual Evoked Potentials as Potential Biomarkers of Visual Function in Patients with Primary Sjögren’s Syndrome

Visual evoked potentials (VEP) are changes in potentials that arise in the central nervous system. In the interpretation of the VEP test results, it is assumed that the elongation of the latency time is caused by the demyelination of the nerve fibers, and the axon damage is responsible for the decrease in the amplitude. The observed VEP deviations are not specific for specific diseases, but indicate disturbances in visual conductivity. VEP may play a diagnostic role in the early detection of visual involvement. The aim of the study was the functioning of visual pathway assessment on the basis of visual evoked potentials (VEP) examination, in patients with primary Sjögren’s Syndrome (pSS), without focal symptoms of central nervous system disorder. The effect of disease activity, as assessed by clinical parameters and antibody levels (anti-Ro52, SSA, and SSB), on the central nervous system was also evaluated. Thirty-two consecutive patient with pSS (31 females, 1 male) were included in the study. VEP was performed at baseline, and after 6 (T6) years. Their results were compared longitudinally between the baseline and T6, depending on the duration of the disease and treatment. The immunological activity of pSS was also analyzed. The group of patients showed a significant prolongation of the P100 implicit time (105.5 ± 5.1 vs. 100.6 ± 3.9; p = 0.000) and a significant higher the P100-N145 amplitude (12.3 ± 4.1 vs. 9.4 ± 3.0; p = 0.000). Abnormalities in electrophysiological parameters of VEP at baseline correlated with presentation of anti-Ro52 antibodies and aching joints. At baseline, the P100 implicit time was shorter for the patients with pSS than for those at T6 (105.50 ± 5.1 vs. 109.37 ± 5.67; p = 0.002). pSS patients without CNS involvement presented with dysfunction of visual pathway, as revealed by VEP abnormalities. Relationships were found between VEP parameters and with present of anti-Ro52 antibodies and aching joints. VEP may be a useful method for assessment and monitoring of subclinical visual deficit in the course of pSS.

O-EV003. Role of multifocal electroretinogram in assessment of early retinal dysfunction in hypertensive patients

Introduction . Hypertensive retinopathy is the second most common cause of retinopathy following diabetes, probably caused by retinal ischemia as a consequence of atherosclerotic irreversible changes of systemic hypertension. Non-uniform functional retinal abnormalities are difficult to detect by full-field ERG and needs the disease to reach advanced changes to be affected. mfERG offers an objective noninvasive and reliable method to measure retinal function. It allows simultaneous recording of local ERG responses from different parts of the retina. Also previous studies suggested that the abnormalities in retinal electrophysiological studies usually precede fundus signs of retinopathy as mfERG is affected early by the neurodegenerative process. our aim in this study was to investigate localized retinal dysfunction in hypertensive patients using multifocal electroretinogram (mfERG) and to assess its sensitivity as an early predictor for the development of retinopathy in hypertensive patients. Methods . Ninety-eight eyes were included in this case-control study. Twenty-eight eyes of healthy subjects served as a control group (group I). Seventy eyes belonged to patients with systemic hypertension assigned into two groups; group II including 39 eyes of hypertensive patients with normal fundus and group III including 31 eyes of patients with signs of hypertensive retinopathy. All participants were subjected to complete ophthalmic and electrophysiological examination using mfERG. N1 and P1 wave amplitudes and implicit times from the central hexagon and four concentric rings across the visual field were analyzed. Results . mfERG amplitudes were significantly reduced in hypertensive group with retinopathy than in controls. N1 amplitude was significantly reduced in the most eccentric ring in eyes of hypertensive patients with normal fundus. Conclusion . mfERG is a sensitive objective tool for assessment of retinal dysfunction in hypertensive patients. mfERG amplitude is a promising predictor for early development of retinopathy in systemic hypertension.

Assessment of Macular Function by Multifocal Electroretinogram in Patients with Multiple Sclerosis Treated with Fingolimod.

IntroductionThis study aimed to evaluate whether treatment with fingolimod (FTY) may induce functional changes on the macular pre-ganglionic retinal elements in patients affected by relapsing–remitting multiple sclerosis (RR-MS) without optic neuritis (ON).MethodsThis case–control observational and retrospective study assessed multifocal electroretinogram (mfERG) responses from 35 healthy controls (mean age 43.58 ± 5.76 years), 41 patients with RR-MS without ON (mean age 40.64 ± 4.83 years, MS-noFTY group), and from 21 patients with RR-MS without ON (mean age 42.38 ± 12.34 years) and treated with fingolimod (Gilenya®, Novartis Europharm, 0.5 mg/day) (MS-FTY group). MfERG N1 and P1 implicit times (ITs), and N1–P1 response amplitude densities (RADs) were measured from concentric rings (R) with increasing foveal eccentricity: 0–5° (R1), 5–10° (R2), 10–15° (R3), 15–20° (R4), 20–25° (R5). We considered R1 and R2 as “central macular areas” and R3, R4 and R5 as “more eccentric retinal areas”. In the MS-FTY group, mfERG recordings were performed between 6 and 12 months (mean 7.2 ± 1.5 months) from the start of FTY.ResultsIn the MS-FTY group, the mean values of mfERG N1 and P1 ITs and RADs detected in both central macular areas (R1 and R2) and in more eccentric retinal areas (R3, R4 and R5) were not significantly different (p > 0.01) with respect to those of control and MS-noFTY groups.ConclusionsOur mfERG results suggest that the chronic use of FTY does not induce a dysfunction of pre-ganglionic retinal elements located in the 0–25° of central retina. Since FTY does not cause any retinal functional abnormality, we suggest that FTY treatment could not produce any toxic effect on pre-ganglionic retinal elements even in the absence of macular oedema.

Multifocalelectroretinography Result before and after Peribulbar Injection of Allogeneic Umbilical Cord – Mesenchymal Stem Cell Secretome for Late-Stage Retinitis Pigmentosa

Background: Retinitis Pigmentosa (RP) is a rare retinal genetic disease without available treatment to date. Previous studies show growth factor and regenerative ability of secretome from cultured allogeneic umbilical chord mesenchymal stem cells (UC-MSC). This studyaimed to report multifocal electroretinography of retinal photoreceptor responsefrom RP patients, before and after injection of secretome from allogeneicUCMSC.Patients and Methods: Four subjects with severely damage retina (visual field defect of 25 %- 50% in initial Humphrey perimetry examination) were recruited and givenperibulbar injection of secretome from allogeneic cultured UC-MSC. Visual acuity, visual field examination, multifocal electroretinogram of retinal photoreceptor examination were observed before and periodically after injection until six months periodResults: Overall, we observed subtle changes in N1 and P1 amplitude and implicit time only in ring 1 at 1, 3 and 6 month post secretome injection. Conclusion: Peribulbar injection of allogeneic UC-MSC secretome had very miminal influence on photoreceptor activity in late-stage RP patients.

Visual Evoked Potential Responses after Photostress in Migraine Patients and Their Correlations with Clinical Features.

In the past few years, researchers have detected subtle macular vision abnormalities using different psychophysical experimental tasks in patients with migraine. Recording of visual evoked potential (VEP) after photostress (PS) represents an objective way to verify the integrity of the dynamic properties of macular performance after exposure to intense light. VEPs were recorded before and after PS in 51 patients with migraine (19 with aura (MA) and 22 without aura (MO) between attacks, and 10 recorded during an attack (MI)) and 14 healthy volunteers. All study participants were exposed to 30 s of PS through the use of a 200-watt bulb lamp. The P100 implicit time and N75-P100 amplitude of the baseline VEP were compared with those collected every 20 s up to 200 s after PS. VEP parameters recorded at baseline did not differ between groups. In all groups, the VEP recordings exhibited a significant increase in implicit times and a reduction in amplitude at 20 s after the PS. In migraine, the percentage decrease in amplitudes observed at 20 s after photostress was significantly lower than in healthy volunteers, in both MO and MA patients, but not in MI patients. When data for MO and MA patients were combined, the percentage of amplitude change at 20 s was negatively correlated with the number of days that had elapsed since the last migraine attack, and positive correlated with attack frequency. We showed dynamic changes of recovery of VEP after PS depending on the migraine cycle. This finding, in conjunction with those previously attained with other neuromodulatory interventions using VEPs, leads us to argue that migraine-disease-related dysrhythmic thalamocortical activity precludes amplitude suppression by PS.

Multifocal electroretinography-assisted anatomical and functional evaluation of subthreshold green laser in acute central serous chorioretinopathy.

Purpose:To compare observation versus subthreshold green laser (STL) in acute central serous chorioretinopathy (CSC) in terms of anatomical and functional outcomes.Methods:Prospective randomized interventional study. 30 eyes with the first episode of acute CSC underwent complete ophthalmologic examination, measurement of best-corrected Snellen visual acuity (BCVA), contrast sensitivity (CS), fundus fluorescein angiography (FFA), spectral-domain optical coherence tomography (SD-OCT), and multifocal electroretinography (mfERG) at baseline. Patients were randomized equally to group A (observation) or group B (STL using 532 nm wavelength applied to the leakage point). Outcome measures included BCVA, CS, central foveal thickness (CFT), and mean macular thickness (MMT) on SD-OCT and P1 amplitude and implicit time (IT) on mfERG. Patients were followed up for 6 months.Results:Mean BCVA was comparable between the two groups on follow up; however, mean CS was significantly higher in group B at 6 months (P = 0.032). CFT was significantly lower in group B at 1 month (P = 0.001) and 3 months (P = 0.049); however, this difference was not maintained at 6 months (P = 0.265). P1 amplitude and IT in all 5 rings were comparable between the two groups at baseline. On follow up, P1 amplitude of ring 1 became significantly higher in group B at 3 months (P = 0.036) and 6 months (P = 0.022).Conclusion:Immediate treatment of acute CSC with STL, as compared to conservative management, leads to more rapid resolution on SD-OCT and superior functional outcomes as evidenced by CS and mfERG.

Assessment of optical coherence tomography angiography and multifocal electroretinography in eyes with and without nonproliferative diabetic retinopathy.

Purpose:To examine (i) the retinal structure and function using optical coherence tomography angiography (OCTA) and multifocal electroretinography (mfERG), respectively, in eyes with and without nonproliferative diabetic retinopathy (NPDR), (ii) and their interrelationship between retinal structure (OCTA) and function (mfERG) in the two groups independently.Methods:This was a prospective observational study. One hundred twenty-one eligible participants with type 2 diabetes with No DR (n = 89), or with mild or moderate NPDR (n = 32) underwent ophthalmic examination, ultrawide field-view fundus photography, OCTA, and mfERG. Group differences were assessed using a Mann–Whitney U test. Correlations were assessed using Spearman's rho.Results:There were no significant differences in OCTA measures between the two groups. The mfERG P1 implicit times (rings 1–6) were significantly delayed and P1 response densities in rings 5 and 6 were significantly lower in participants with NPDR compared to those with No DR. In those with No DR, P1 implicit times in almost all rings were delayed in relation to lower vessel density and perfusion (maximum variance noted was 13%). In individuals with NPDR, the P1 response density in rings 2 and 3 showed a positive nonsignificant correlation with macular perfusion.Conclusion:In those with diabetes with No DR, retinal neuronal function is influenced by lower macular vessel density and perfusion. The retinal neuronal function is abnormal in individuals with NPDR compared to those with No DR and is not correlated with OCT angiometric measures, suggesting the likelihood of a different retinal structural correlate.

Multifocal Electroretinogram Alterations after Intravitreal Ranibizumab Treatment in Diabetic Macular Edema.

Objectives:To assess multifocal electroretinogram (mf-ERG) values in patients with diabetic macular edema (DME) who were treated with intravitreal ranibizumab (IVR).Methods:Thirty eyes of patients with DME, who underwent three consecutive monthly injections of IVR and as required thereafter, were evaluated. Best corrected visual acuity (BCVA) (log MAR), optical coherence tomography (OCT) features [diameters of cyst and subretinal fluid, hyperreflective dots (HRDs)], and mf-ERG were evaluated at baseline, 1 month, and 6 months throughout the follow-up period. The correlation of mf-ERG values and OCT features, BCVA, and the duration of disease were investigated.Results:In the study group, the baseline P1 and N1 amplitudes were significantly lower than the control group, and P1 and N1 implicit times were significantly higher in patients with DME than in the control group in all rings (All p<0.05) The mean response density (P1 amplitude, nV/deg2) values increased over 6 months in rings 1, 2, and 3 (p<0.001, p=0.003, p=0.006). There was a negative correlation between the diameter of the cyst and the initial response density of P1 (for horizontal diameter: r=–0.658, p=0.03; for vertical diameter: r=–0.597, p=0.037; for the area of the cyst, r=–0.603, p=0.021). There was a significant negative correlation between the subretinal fluid and HRD reduction and the response density of P1 increase (all p<0.05). At baseline and 6 months, the correlation between BCVA and the P1 and N1 amplitude of the central ring was significant (for baseline P1: r=–0.649, p=0.01; for N1: r=–0.575, p=0.02; for 6-month P1, r=–0.603, p<0.001; for N1: r=–0.591, p=0.005).Conclusion:The combination of OCT and mf-ERG can be used to evaluate the functional recovery in DME.

Anatomical and functional outcomes of subthreshold micropulse laser versus intravitreal ranibizumab injection in treatment of diabetic macular edema

BackgroundTo compare the therapeutic effects of subthreshold micropulse laser (SML) versus intravitreal injection of ranibizumab in treatment of diabetic macular edema (DME) both anatomically using optical coherence tomography (OCT) and functionally using best corrected visual acuity (BCVA) and multifocal electroretinogram (mfERG).Methodshis study was an interventional prospective randomized comparative study. The study included 120 eyes classified into 3 groups: Group 1 included 40 eyes of 28 patients treated by SML laser, group 2 included 40 eyes of 32 patients treated by intravitreal injection of ranibizumab, and group 3 (control group for mfERG) included 40 eyes of 20 patients with diabetes mellitus (DM) of more than 10 year duration with no signs of diabetic retinopathy (DR). BCVA measurements, OCT and mfERG were done for the cases before and after interference and were followed up for 6 monthsResultsBy the end of the follow up period, BCVA significantly improved by 31% in group 1 vs 93% in group 2 with a statistically highly significant difference between the two groups (p value < 0.001). There was also a significant decrease in central subfield thickness in both groups with more reduction in group 2 compared with group 1 (p value < 0.001). There was a significant improvement in P1 amplitude of mf-ERG in group 2 (p value < 0.002) with no significant improvement in group 1. There was a significant decrease in P1 implicit time in group 2 (p value < 0.001) while there was no significant decrease in group1.ConclusionsIntravitreal injection of ranibizumab is a superior treatment modality for DME compared with SML regarding both anatomical and functional outcomes.Trial registration: This study has been approved by the local ethical committee of faculty of medicine of Minia University and retrospectively registered at the clinical trial gov. with Identifier: NCT04332133.

Functional Assessment of Outer and Middle Macular Layers in Multiple Sclerosis.

The involvement of macular preganglionic elements’ function, during the neurodegenerative process of multiple sclerosis (MS), is controversial. In this case-control observational and retrospective study, we assessed multifocal electroretinogram (mfERG) responses from 41 healthy Controls, 41 relapsing-remitting MS patients without optic neuritis (ON) (MS-noON Group) and 47 MS patients with ON: 27 with full recovery of high-contrast best corrected visual acuity (BCVA) (MS-ON-G Group) and 20 with poor recovery (between 0.2 and 1 LogMAR) of BCVA, (MS-ON-P Group). In the latter Group, Sd-OCT macular volumes and thicknesses of whole and inner and outer retina were measured. MfERG N1 and P1 implicit times (ITs), and N1-P1 response amplitude densities (RADs), were measured from concentric rings (R) with increasing foveal eccentricity: 0–5° (R1), 5–10° (R2), 10–15° (R3), 15–20° (R4), 20–25° (R5), and from retinal sectors (superior, nasal, inferior and temporal) between 0–15° and 0–25°. In the MS-ON-P Group, mean mfERG RADs detected from R1 (0–5°) and from the central nasal sector (0–15°) were significantly reduced (p < 0.01) with respect to those of the Control, MS-noON and MS-ON-G Groups. No other significant differences between Groups for any mfERG parameters were found. All Sd-OCT measurements, apart from the inner retina macular volume in the central 1 mm, were significantly reduced in MS-ON-P patients compared to Controls. The functional impairment in the MS-ON-P Group was associated but not correlated with structural changes of the outer and inner retinal layers in corresponding retinal Areas and Sectors. Our results suggest that in MS, exclusively after ON with poor recovery of BCVA, the neurodegenerative process can induce dysfunctional mechanisms involving photoreceptors and bipolar cells of the fovea and of the more central nasal macular area.

Functional assessment of early retinal changes in diabetic patients without clinical retinopathy using multifocal electroretinogram

BackgroundWe aimed to assess early retinal changes in diabetic subjects without clinical retinopathy using multifocal electroretinogram (mfERG).MethodsTwenty eyes of 20 diabetic subjects type 2 without retinopathy and 20 eyes of 20 healthy controls of the same age and sex were eligible for our study and underwent mfERG. MfERG responses were recorded; N1–P1 amplitude and P1 implicit time of the 5 rings recorded were measured and analyzed.ResultsThe reduction in N1–P1 amplitude and the delay in P1-implicit time in type 2 diabetic subjects were statistically significant in most of the assessed rings compared to controls (p < 0.001). Moreover, N1–P1 amplitude was negatively correlated with diabetes duration. However, there was a positive correlation between P1-implicit time and diabetes duration in type 2 diabetic subjects in four out of five rings (p < 0.001).ConclusionsOur study showed reduced mfERG N1–P1 amplitude and delayed P1-implicit time indiabetic patients without retinopathy compared to normal controls. Implicit time andamplitude were significantly affected by diabetes duration. These results propose a valuable role of mfERG in evaluating the expected neuroretinal dysfunction before the clinical development of diabetic retinopathy. Early detection of functional abnormalities indicates that the patients need more tight medical control of diabetes. More well-designed studies are needed to assert upon these results.

Multifocal ERG Changes as an Indicator for Short-Term Outcome after Intravitreal Injection of Ranibizumab in Treatment of Diabetic Macular Oedema

Background: compared to laser photocoagulation, intra vitreal injection of anti-vascular endothelial growth factors (Anti VEGFs) have more desirable results and fewer complications. Study of this issue by multifocal electroretinogram (mf-ERG) revealed significant improvement in macular function associated with decreased retinal thickness using optical coherence tomography (OCT) and improvement of best corrected visual acuity (BCVA). Purpose: To study the role of multifocal Electroretinogram in the follow up of diabetic macular edema after intravitreal injection Ranibizumab and study its correlation to visual acuity and optical coherence tomography changes. Methods: A non-randomized prospective study was carried out from February 2018 to August 2018 on 32 eyes of patients with diffuse or focal DME without macular ischemia. The patients were selected from the outpatient ophthalmology clinic of Al-Hussein University hospital. The patients were injected intravitreally by Ranibizumab 0.5mg/0.05mL at baseline, 1 and 3 months. In this study we assessed pre and post-injection BCVA, IOP measurement by applanation tonometer, OCT and multifocal ERG changes over 3 months. Results: log MAR BCVA improved from (0.88±0.12) preoperatively to (0.53±0.18) at the end of the 3rd month, with P-value &lt;0.001. Central subfield thickness 1 mm improved from (408.73±79.40µm) preoperatively to (224.33±32.49µm) at the end of the 3rd month, while para and peri-foveal thickness improved from (402±46.52µm) preoperatively to (286.30±32.67µm) at the end of the 3rd month, with P-value &lt;0.001. P1 amplitude in ring 1 using MF-ERG improved from (33.08±10.59 nv/deg2) preoperatively to (58.30±32.67 nv/deg2) at the end of the 3rd month, with P-value&lt;0.001. P1 amplitude in ring 2 using MFERG improved from (18.82±5.01 nv/deg2) preoperatively to (26.36±3.006 nv/deg2) at the end of the 3rd month, with P-value in the 1st month &lt;0.05, while in the 3rd month &lt;0.001. P1 implicit time in ring 1 using MF-ERG improved from (78.65±12.37 ms) preoperatively to (63.78±15.73 ms) at the end of the 3rd month, with P-value in the 1st month &lt;0.05, while in the 3rd month &lt;0.001. P1 implicit time in ring 2 using MF-ERG improved from (48.81±6.44 ms) to (44.39±4.06 ms) at the end of the 3rd month, with P-value in the 1st and 3rd months &lt;0.05. Complications during follow up of patients especially 1week after injection were relatively uncommon, including mild subconjunctival haemorrhage in 1 eye (3.3%) and transient increase of IOP in 4 eyes (13.33%). Conclusion: Intravitreal injection of Ranibizumab resulted in improvement of macular function in study patients with diabetic macular edema. Postoperative improvement in visual acuity was accompanied by decreased retinal thickness measured by OCT and improvement of P1 amplitude in the central ring measured by MF-ERG.

Foveal structure, function and microvascular morphology in school-age children with laser-treated retinopathy of prematurity.

The purpose of this retrospective case-control study was to evaluate the relationship between foveal structure, function, microvascular morphology and visual acuity in school-age children with laser-treated retinopathy of prematurity (ROP). Foveal structural parameters, including the central foveal thickness (CFT), inner retinal thickness (IRT) and outer retinal thickness (ORT), were measured on B-scans using an Optovue XR Avanti optical coherence tomography device. Foveal microvascular parameters, including the foveal avascular zone (FAZ), superficial capillary plexus-vessel density (SCP-VD) and deep capillary plexus-vessel density (DCP-VD), were measured on optical coherence tomography angiography with a scan size of 3 × 3. The P1 amplitudes and P1 implicit times were recorded by a multifocal electroretinogram with 61 elements. Fifty-five eyes (26 eyes of school-age ROP children and 29 eyes of full-term controls) were analysed. The ROP children manifested a significantly smaller FAZ, higher SCP-VD and higher DCP-VD than the controls (p < 0.001). The CFT (p < 0.001), IRT (p < 0.001) and ORT (p = 0.001) were significantly increased in the ROP group. The P1 amplitudes in all five-ring retinal regions were significantly smaller in the ROP group (p < 0.001). Multivariable analysis indicated that best-corrected visual acuity was positively correlated with post-menstrual age (PMA) and negatively correlated with SCP-VD and CFT (R2 = 0.529, p < 0.001, 0.043 and 0.020, respectively). The foveal structure, function and microvascular morphology are affected in school-age children with laser-treated ROP. PMA, foveal structural anomalies and microvascular changes in ROP children were associated with impaired visual function.